Electric control mechanism.



No. 726,593.. 7 PATEN'TED APR. 28-, 1903.

E. THOMSON. ELECTRIC OONTROL MECHANISM.

. nrmonmn rum) 001229, 1900. no MODEL. 2 SHEETS-SHEET 1-. v

Fig-.1.

v 1 SSEE I I I \/E: El

E M W M i; W M v 5;

No. 726,593. PATENTED-APR. 28, 1903. E. THOMSON,

ELECTRIC CONTROL MECHANISM.

APPLICATION FILED 001*. 29, 1900. N01 MODEL. 2,8HEETS-SHEBT 2.

Fi -6f v INVBNT UL. Ehhu Thomson THE mums vzrzns co, Mow-unisvWASNNGTON. a c.

WNITED STATES "ATENT (demos.

ELII-IU THOMSON, OF SVVAMPSCOTT, MASSACHUSETTS, ASSIGNOR TO GEN- ERALELECTRICCOMPANY, A CQRPORATION'OF NEW YORK.

ELECTRIC ooNTRoL M ECHANISM.

SPECIFICATION forming part of Letters. Patent No. 726,593, dated April28, 1903.. Application filed October 29,1900. Serial No. 34,685. (Nomodel.)

To all whom it may concern.-

Be it known that I, ELIHU THOMSON, a citizen of the United States,residing at Swampscott, county of Essex,State of Massachusetts,

this particular relation. Therdevice may be used to out resistance intoor out of circuit step by step and may be used in connection withelectric-motor controllers for performing the desired variations ofresistance. When so used, I employ a locking device whereby thecontroller is locked during the time the device is cutting'resistanceout of circuit and is only unlocked after the resistance has beenremoved, or vice versa, as the case may be.

I have shown my'invention as embodied in a system of control whereby acontroller is used for connecting two motors in series or in parallel.In this case the step-by step changes of resistance are effected, not bymeans of contacts on the controller-cylinder, but by the independentmovement of the separate circuit-changing device which I em ploy. Thisdevice is electromechanically actuated and is brought into operation bythe controller by which it is connected into circuit when its operationis desired anddis connected when not needed. Such in a general way isthe nature of my i n-vent ion,the scope of which will be moreparticularly,

pointed out in the claims'appended' thereto.

For a more detailed understanding of my invention and its mode ofoperation reference is to be hadto the following description, taken inconnection with the accompanying drawings, in which Figure 1 is adiagrammatic view of a circuit-closing device arranged in accordancewith my invention and cooperatively associated with acontroller-cylinder. Fig. 2 represents a different position of the partsof the arrangement shown in Fig. 1. Figs. 3 to 8,

inclusive, are conventional diagrams showing how the controller andadjunctive device shown in Fig. 1 may be used for the seriesparalleloperation of electric motors.

Referring to Fig. 1, H represents the handie of a controller, thecylinder of which is shown at O. This cylinder is provided with contactsarranged according to the scheme shown in Figs. 3 to 8, these contactscooperating with contact-fingers, also indicated in the figuresmentioned. Oneof these fingers (shown at a in Fig. 1) cooperates withthe contact I) on the controller-cylinder to connect in circuit theresistance R and the wind ing of the magnet M. This magnet acts upon apivoted armature L, one end of which is provided with a contact-fingerd, which as the ar mature moves about its axis slides over a series offixed contacts e, connected to suitablyspaced points in the resistanceR. A spring S, connected at one end to the armature-lever L and at theother to the supporting-frame F, serves to urge the armature-levertoward one of its extreme positions, in which the resistance R iscompletely out into circuit with the winding of the magnet M. When themagnet M is energized, the armature-lever is moved in theopposite-direction, so as to cut out the resistance, this motion,however, being rendered comparatively slow by means of a dash-pot D orother suitable device. The

piston of this dash-pot is provided with a check-valve g, which isclosed while the armature-lever is being attracted by its magnet, thusrendering the motion of the lever slow, and opened as the lever moves inthe opposite direction. The result is that the resistance B when outinto circuit is then slowly out out of circuit step by step, but on thereturn motion of the armature-lever is rapidly inserted.

When the controller-handle H is moved to its first position, a stop Pbrings up against onearm h. of a three-armed lever L A spring Z normallyurges the arm it into the path of the stop P. When the armature L isattracted by the magnet M, one end of the armature-lever brings upagainst a projecting end of the arm I of the three-armed lever L therebyrotating the lever L about its axis and withdrawing the arm h fromengagement with the stop P.

During the passage of the contact 61 over the fixed contacts 6 of theresistance R the controller is thus locked from movement and is onlyunlocked, as described, upon the completion of the circuit-changingaction of the armature L.

Fig. 2 shows the position of parts after the magnet M has been energizedand the circuitchanging lever-armature L moved thereby to one of itsextreme positions. In this position one end of the lever is shown inengagement with a projecting end of the arm I of the lever L Thisforcible engagement is suificient to move the arm 71 out of lockingengagement with the stop P on the controller. The controller is thusfree to be moved into succeeding positions, as may be desired.

In order to make the speed of movement of the armature L of the samedegree of slowness when attracted by the magnet M, whatever be thecurrent fiowing in the winding of the magnet, I may proportion the coreof the magnet so as to be saturated by a comparatively small current,whereby if any larger current should flow the attractive force of themagnet would not be greatly increased and would therefore not cause muchincrease in speed of movement of the armature.

The magnetically-actuated circuit-changing device which I have abovedescribed is obviously capable of application in many relations where itis desired that the circuit changes should be performed independently ofmanual control. In Figs. 3 to 8 of the drawings I have shown theapplication of my device to a series-parallel system of motor control,the device acting in this instance to vary the resistance in circuitwhen such variation is desired. In such a system my device isadvantageous in that it allows the contacts for changing the resistancein circuit to be located elsewhere than upon the controller-cylinder,thereby lessening the complicaiion of parts of the controller with itsattendant advantages. It is also advantageous in that the variation ofresistance is independent of manual control.

In Fig. 3 two motors are shown, the armatures of which are indicated,respectively, at A A and the fields at F F The resistances for the twomotors are shown at R and R each of these resistances being providedwith a magnetically-actuated circuit-changing device for slowly cuttingthe resistance out of circuit. All of the parts thus mentioned are cutinto or out of circuit and their circuit relations changed by means ofcontacts upon the controller-cylinder operating in conjunction withcontact-fingers in the usual manner. In the first position of thecontroller the contacts 1, 2, 3, 4:, 5, 6, and 7, cooperat ing with th econtact-fingers which hear thereon, as shown, operate to connect themotors and resistances all in series between the trolley T and theground-return E, the magnetic circuit-changing devices M and M being inthis position out of circuit. In the next position of the controller(shown in Fig. 4) the connections are the same as in Fig. 3, except thatthe magnetic circuit-changing device M is connected in circuit, theconnection being effected by disconnecting the terminal 8 of theresistance R and substituting the terminal 9 of the winding of themagnet M, the circuit,however,beingstill completed through theresistance R by reason of the connection of the other end of the windingthrough the arm 10 and moving contact 11. As soon as this connection ismade the moving contact 11 is caused to slowly pass over the fixedcontacts 12 in the manner already described, the resistance B being thusslowly cut out of circuit. The final position of the parts is shown inFig. 4. In the next position of the controller the same transposition ofthe terminals is made with respect to the magnetic circuit-changingdevice M and the resistance R which it controls. After the device M hasthus been actuated the connections are as represented at Fig. 5, inwhich both motors are connected directly in series between the trolleyand ground without the interposition of any resistance. The furthercircuit changes effected by the controller are made with a view toconnecting the motors in parallel relation with each other. Preparatoryto attaining this object the controller first shunts one of themotorsas, for example, the motor A this connection being effected bymeans of the contacts 13 14, which are electrically connected together.Simultaneously therewith the magnet M is cut out of circuit, thuscausing the rapid insertion of the resistance R. The contact 14 beinggrounded thus serves to connect the motor A in series with resistance Rdirectly between the ground and the trolley T, as will readily be seenfrom Fig. 6. In the next position of the controller the resistance R isdisconnected from the terminal 15 of the motor A and by means of theelectricallyconnected contacts 16 17 is put into direct connection withthe trolley T, all of which will be readily apparent in Fig. 7. The twomotors are thus connected in parallel with each other between trolleyand ground, the respective resistances of the two motors being, however,connected in circuit with the motors in order to prevent a too-suddenrush of current. In order to increase the torque of the motors, the nextstep of the controller acts to insert the magnetic circuit-controllin gdevices for the resistances, the connections being readily apparent inFig. 8. As soon as these devices are put in circuit their armatu res areslowly attracted and the resistances slowly cut out of circuit, themotors being then directly connected in the supply-circuit without theinterposition of resistance, thereby receiving the full voltage of thesupplycircuit and developing their maximum torque.

It is obvious that my invention is capable of may other applicationsthan that shown and of course maybe applied to alternatingcurrentcircuits as well as to those fed by direct current. Instead of effectingthe varia tion of resistance the circuit-changing device may causevariations of reactance, variations in the number of turns of a winding,as well as other circuit changes which it may be found desirable to makeindependent of manual control.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is-

1. The combination of a controller, a mechanically-actuated lockingdevice or detent for the controller, a resistance, and magnetic meansfor successively varying said resistance and releasing said lockingdevice.

2. The combination of a controller, a mechanically-actuated lockingdevice or detent for the controller, a resistance, and slow-actingmagnetic means for successively varying said resistance and releasingsaid locking device.

3. The combination of a controller, a looking device or detent for saidcontroller, a resistance adapted to be connected in circuit by saidcontroller, and means for automatically cutting said resistance out ofcircuit and releasing said locking device or detent.

4c. The combination of a controller, a current-limiting device adaptedto be connected in circuit by said controller, electrically-controlledmeans for disconnecting said currentlimiting device, a detent for thecontroller, and means for releasing the detent when the saidcurrent-limiting device is cut out of circuit.

5. The combination of an electric circuit,

I a current-limiting device, manually-actuated means for connecting thecurrent-limiting de vice in circuit, means independent of manual controlfor removing the current-limiting device, and a locking device or detentfor the manually-actuated means.

6. The combination of a controller, a resistance adapted to be connectedin circuit by said controller, slow-acting means for-disconnecting saidresistance, and a detent for said controller brought intooperation whilesaid resistance or part thereof is in circuit.

'7. The combination of an electric circuit,aresistance,manually-actuated means for con: necting the resistance incircuit, magnetic means for removing the resistance, and a lookingdevice or detent, independent of manual control, for themanually-actuated means.

8. The combination of an electric circuit, a current-limiting device,manually-actuated means for connecting the current-limiting device incircuit, magnetic means for removing the resistance, and a lockingdevice or detent released by said magnetic means.

9. In a system of motor control, the combination of a plurality ofelectric motors, manually-actuated means for connecting the motors inseries and in parallel, resistances adapted to be connected in circuitwith said motors, and means independent of manual control for varyingsaid resistances.

10. In a system of motor control, the combination of a plurality ofelectric motors, manually-actuated means for connecting the motors inseries and in parallel, resistances adapted to be connected in circuitwith said motors, and means independent of manual control for slowlycutting out said resistances.

11. The combination of a controller, a device adapted to be connected incircuit bysaid controller, meansindependent of manual control forcutting said device out of circuit, and

a detent or locking device for said controller controller and providedwith a plurality of contacts, means independent of manual control forcutting said device out of circuit, and a detent or locking device forsaid controller operative until said device has been cut out of circuit.

In witness whereof I have hereunto set my hand this 26th day of October,1900.

ELIHU THOMSON.

Witnesses:

DUGALD MOKILLOP JOHN MOMANUS.

